Archive for the ‘General’ Category

OK, this is different of what I use to write but I think it would be helpful for all iphone 4 users.

I had my iphone 4 few days back and I was quite impressed by this new smartphone until I realized the phone is draining my battery like a Ferrari sucks up fuel. All that iphone 4 claims of long life battery etc seems rubbish to me. I went through several forums and did some tests to come up with some guidance notes to avoid battery drain for iPhone 4. This can also be used for other iphone generations.

  • Don’t over charge your battery, drain it to 10% and below and then charge it completely to 100% and take the Power cable off. Don’t leave it charging overnight as that damages the Battery cell. Go into General > Usage > Battery Percentage > ON. This will show you battery life in %.
  • Go to Safari browser and close all webapges. Don’t leave pages running in background after you use Safari.
  • if you find your iPhone is getting hot and battery is draining fast then Reboot your iphone but shuting it down and bringing it back up. This way it will kill any process using up iphone resources.
  • Go to Settings > Wifi > Turn it off if not using it. Also under wi-fi turn off “Ask to join Networks” if you already have added your wifi network
  • Under Notifications > Turn it off. I found that my fring Software was taking a lot of battery resources as that was set as Notifications turned on by default. I still have my facebook notifications ON but keep it off if you don’t need notifications.
  • Under Settings > Sounds >Ring > Vibrate off. I have also turned off New mail, Sent mail, Calendar Alerts, Lock Sounds.
  • Under Settings > Brightness > Turn Auto Brightness ON
  • From Settings > General > Network > Enable 3G > off
  • From Settings > General > Network > Turn off Internet Tethering if don’t use it
  • Settings > General > Spotlight Search > Uncheck all – This is a major battery drainer
  • Turn off Push from Settings > Mail Contacts and set it to Fetch > manual
  • Settings > Messages > MMS messages > off – if you don’t use MMS often
  • If this all doesn’t resolve the issue then you need to restore your iphone as a new phone and not as backup. Hook it into itunes and restore it as new phone

Note: I can now confirm that after following the above tips my battery ran for 56 hours+ with a usage of 7hours+ which include playing games like iBasket, FruitNinja and paper Toss as well as facebook browsing. Also, I did some facetime Video calls as well. Just to add that my iphone 4 has not been created as new phone but has been created from my iphone 3G backup.

RTP: Voice payloads are encapsulated by RTP, then by UDP, then by IP. A Layer 2 header of the correct format is applied; the type obviously depends on the link technology in use by each router interface. A single voice call generates two one-way RTP/UDP/IP packet streams. UDP provides multiplexing and checksum capability; RTP provides payload identification, timestamps, and sequence numbering.

Each RTP stream is accompanied by a Real-Time Transport Control Protocol (RTCP) stream. RTCP monitors the quality of the RTP stream, allowing devices to record events such as packet count, delay, loss, and jitter (delay variation). A single voice packet by default contains a payload of 20 msec of voice (either uncompressed or compressed). Because sampling is occurring at 8000 times per second, 20 msec gives us 160 samples. If we divide 8000 by 160, we see that we are generating 50 packets with 160 bytes of payload, per second, for a one-way voice stream.

G711 G729
Payload 160 b 20 b
Codec BW 64kbps 8kbps
L3/L4 header:
RTP 12 12
UDP 8 8
IP 20 20
Protocol Payload 40 40
Total before L2 200 b 60 b
Bamdwidth/call = Payload + Protocol Payload / Payload x CodecBW
BW/call (without L2) (160+40)/160 x 64 = 80kbps (20+40)/20 x 8 = 24kbps
Frame Relay Overhead
Frame Relay 6 b 6 b
Total L2 206 b 66 b
BW/call (160+(40+6))/160 x 64 =82.4 kbps (20+(40+6))/20 x 8 = 26.4kbps
Multilink PPP Overhead
Multilink 6 b 6 b
Total L2 206 b 66 b
BW/call (160+(40+6))/160 x 64 =82.4 kbps (20+(40+6))/20 x 8 = 26.4kbps
Ethernet Overhead
Ethernet 18 b 18 b
Total L2 218 b 78 b
BW/call (160+(40+18))/160 x 64 =87.2 kbps (20+(40+18))/20 x 8 = 31.2kbps
cRTP Applied
CRTP 40 => 4 40 => 4
Before L2 160+4 / 160 x 64 =65.6kbps 20+4 / 20 x 8= 9.6kbps
After L2 160+(4+6) / 160 x 64 =68kbps 20+(4+6) / 20 x 8= 12kbps
% GAIN with cRTP 18% 60%

Useful Parameters

Posted: August 14, 2010 in General

Following are useful parameters to be changed all in one go:

Enterprise Parameters:

Auto Registration Phone Protocol = SCCP << Very Important if this is SIP then all your phones will load SIP firmware

Connection Monitor Duration = 10  << Default is 120, by minimizing the time duration, you can speed up your the process of your phones falling back to Primary Call manager from SRST

Phone URL Parameters = Change the hostnames to IP addresses << If this is not done then many phone services will not be accessible.

Service Parameters:

T302 Timer = 5000  << Interdigit time-out
G722 Codec Enabled  = False

Stop Routing on Unallocated Number Flag = False
Max Forward UnRegistered Hops to DN = 2

Transfer On-hook Enabled = Enabled
Forward No Answer Timer = n

Default Inter-Presence Group Subscription = Allow Subscription
CUP PUBLISH Trunk = <SIP TRUNK for CUPS server>

Device Name of GK-controlled Trunk That Will Use Port 1720 = GK-Trunk
Intraregion Audio Codec Default = G729  << This is Important for Gatekeeper calls

Built-in Bridge = Enable

Message waiting Lamp Policy = Primary Line – Light and Prompt

Preferred G.729 Millisecond Packet Size = n ms

Allow TCP Keepalive for H323 = False
Allow peer to preserve call = True

Call Park Reversion Timer  = n

n= any value as per requirememt

This is just notes to myself as after downloading the upgrade files for CUCM or Unity or anything else…we all need to follow the same process of combining them and then verifiying the hash value.

Download FCIV.

Download the files as required:



Run the following command to combine these files into one .iso file

COPY /B C:\UCS_Install_UCOS_7.1.3.32900-4.sgn.iso_part1of2+C:\UCS_Install_UCOS_7.1.3.32900-4.sgn.iso_part2of2 C:\UCSInstall_UCOS_7.1.3.32900-4.sgn.iso


Use a checksum generator to confirm that the MD5 checksum of the reunited file matches the following checksum:


If the values do not match, the reunited file is damaged.

C:\>cd fciv

C:\FCIV>fciv.exe c:\UCSInstall_UCOS_7.1.3.32900-4.sgn.iso
// File Checksum Integrity Verifier version 2.05.
d450666dafbc8f01c111ed0158f748fb c:\ucsinstall_ucos_7.1.3.32900-4.sgn.iso


Note: Make sure if you are writing it over a CD/DVD then it should be copied as Data and don’t expand it as an image. The file on the CD/DVD should be a .iso file as Call manager only looks for this file.

Now you can run the upgrade process either from OS Admin or CLI. I prefer CLI but any method can be used.

Disable throttle to speed up the process, Throttling prevents call processing degradation during the upgrade but may cause the upgrade to take longer. Throttling gets enabled by default and is necessary if you perform the upgrade during normal business hours.

Upgrade Process from CLI:

First of all disable ios throttle by using command utils iothrottle disable. If it’s not disabled at start, you will be asked during the upgrade as well where you may or may not disable it.

admin:show version active
Active Master Version:

Active Version Installed Software Options:

admin:utils system
utils system boot*
utils system restart
utils system shutdown
utils system switch-version
utils system upgrade*

admin:utils system upg
admin:utils system upgrade ini
admin:utils system upgrade initiate

Warning: Do not close this window without first exiting the upgrade command.

To preserve system stability during upgrades, the system throttles the upgrade process, which may take considerably longer to complete.  If you are performing this upgrade during a maintenance window and want to speed up the upgrade, you can disable throttling.  Additional information is in the Special Upgrade Information section of the release notes.

Would you like to disable I/O throttling (yes/no): yes


1) Remote Filesystem
q) quit

Please select an option (1 – 2 or “q” ): 1
Directory: \
User Name: cisco
Password: *****

1) sftp
2) ftp
q) quit

Please select an option (1 – 2 or “q” ): 1
Checking for valid upgrades.  Please wait…

Available options and upgrades in “\”:

1) UCSInstall_UCOS_7.1.3.32900-4.sgn.iso
q) quit

Please select an option (1 – 1 or “q” ): 1
Accessing the file.  Please wait…

[KDownloaded 2 MB. [KDownloaded 5 MB. [KDownloaded 8 MB. [KDownloaded 11 MB.
[KDownloaded 15 MB. [KDownloaded 18 MB.[KDownloaded 21 MB.[KDownloaded 24 MB.
[KDownloaded 27 MB.[KDownloaded 31 MB.[KDownloaded 34 MB.[KDownloaded 37 MB.
[KDownloaded 40 MB.[KDownloaded 43 MB.[KDownloaded 45 MB.[KDownloaded 48 MB.



KDownloaded 3206 MB.[KDownloaded 3209 MB.[KDownloaded 3211 MB.[KDownloaded 3214 MB.
[KDownloaded 3216 MB.[KDownloaded 3219 MB.[KDownloaded 3222 MB.[KDownloaded 3225 MB.
[KDownloaded 3227 MB.[KDownloaded 3230 MB.[KDownloaded 3233 MB.[KDownloaded 3236 MB.

Checksumming the file…

KDownloaded 3236 MB.File validated.

A system reboot is required when the upgrade process completes or is canceled.  This will ensure services affected by the upgrade process are functioning properly.

Downloaded: UCSInstall_UCOS_7.1.3.32900-4.sgn.iso
File version:
File checksum: d4:50:66:6d:af:bc:8f:01:c1:11:ed:01:58:f7:48:fb

Automatically switch versions if the upgrade is successful (yes/no): no

Start installation (yes/no): yes
The upgrade log is install_log_2010-08-
Upgrading the system.  Please wait…
08/26/2010 10:41:10|Starting|<LVL::Info>
08/26/2010 10:41:10|Parse argument method=sftp|<LVL::Debug>
08/26/2010 10:41:10|Parse argument source_dir=\|<LVL::Debug>
08/26/2010 10:41:10|Parse argument dest_file=/var/log/install/downloaded_versions|<LVL::Debug>
08/26/2010 10:41:10|Parse argument remote_host=|<LVL::Debug>
08/26/2010 10:41:10|Parse argument user_name=cisco|<LVL::Debug>
08/26/2010 10:41:10|Calling SFTP command with metering off|<LVL::Debug>
08/26/2010 10:41:11|SFTP command complete (0)|<LVL::Debug>
08/26/2010 10:41:11|List file (pre-filtered):|<LVL::Debug>
08/26/2010 10:41:11|(CAPTURE) UCSInstall_UCOS_7.1.3.32900-4.sgn.iso|<LVL::Debug>



08/26/2010 12:18:22|CSA Status = 0|<LVL::Debug>
08/26/2010 12:18:22|/etc/init.d/ciscosec start|<LVL::Info>
08/26/2010 12:18:24|(CAPTURE) Starting ciscosec:  [  OK  ]|<LVL::Debug>
08/26/2010 12:18:24|IOWAIT monitor stopped|<LVL::Info>
08/26/2010 12:18:24|0|<LVL::Debug>
08/26/2010 12:18:24|Upgrade Complete — (0)|<LVL::Info>

Successfully installed UCSInstall_UCOS_7.1.3.32900-4.sgn.iso

The system upgrade was successful.  Please switch versions to activate the upgrade or reboot the system to ensure services affected by the upgrade process are functioning properly.



admin:utils system swi
admin:utils system switch-version

Active Master Version:

Inactive Master Version:

If you are switching to an earlier release, you must run:

utils dbreplication reset all

from the publisher after all the nodes are switched over.

Do you really want to switch between versions ?

Enter (yes/no)? yes

Switching Version and Restarting the Appliance …

Switch version duration can vary depending on the database size
and platform configuration.  Please continue to monitor the
switchover process from here.

Waiting …………………………………………………………………………………………………………………………..

Broadcast message from root (Thu Aug 26 12:30:09 2010):

The system is going down for reboot NOW!


Operation succeeded


After this restart the server@

admin: utils system restart

Once it come  back up, check the services

admin:utils service list

{ The box I was upgrading was a Subscriber so I had to make sure if replication is all f ine }


admin:file view activelog cm/trace/dbl/sdi/ReplicationStatus.2010_08_26_15_38_33.out

g_darcuc_ccm7_1_3_32900_4    2 Active   Local           0
g_goscuc_ccm7_1_3_32900_4    3 Active   Connected       0 Aug 26 15:34:16


No Errors or Mismatches found.
Replication status is good on all available servers.

admin:show perf query class “Number of Replicates Created and State of Replication”
==>query class :

– Perf class (Number of Replicates Created and State of Replication) has instances and values:
ReplicateCount  -> Number of Replicates Created   = 427
ReplicateCount  -> Replicate_State                = 2


admin:utils dbreplication status

——————– utils dbreplication status ——————–

Replication status check is now running in background.
Use command ‘utils dbreplication runtimestate’ to check its progress

The final output will be in file cm/trace/dbl/sdi/ReplicationStatus.2010_08_26_15_39_17.out

Please use “file view activelog cm/trace/dbl/sdi/ReplicationStatus.2010_08_26_15_39_17.out ” command to see the output
admin:file view activelog cm/trace/dbl/sdi/ReplicationStatus.2010_08_26_15_39_17.out

g_darcuc_ccm7_1_3_32900_4    2 Active   Connected       0 Aug 26 15:34:16
g_goscuc_ccm7_1_3_32900_4    3 Active   Local           0

No Errors or Mismatches found.
Replication status is good on all available servers.

options: q=quit, n=next, p=prev, b=begin, e=end (lines 1 – 20 of 20) :
admin:show perf query class “Number of Replicates Created and State of Replication”
==>query class :

– Perf class (Number of Replicates Created and State of Replication) has instances and values:
ReplicateCount  -> Number of Replicates Created   = 427
ReplicateCount  -> Replicate_State                = 2

If the count is ‘3’ then you may have replication issues. Follow the steps to resolve replication issues:

  • Utils debreplication stop on Subscriber
  • Utils debreplication stop on Publisher (once you stopped Subscriber)
  • Utils dbreplication reset all (from Publisher)
  • If needed restart Subscriber

This will fix the issue. Sometimes I did came across a misleading message after repairing replication. It was like:

admin:utils dbreplication reset all
Replication reset is in progress. Replication setup will continue in background.
Please watch RTMT replication state on all nodes. It should go from 0 to 2.
When all subs have an RTMT Replicate State of 2, replication setup is complete.
If RTMT Replicate State shows 4, there is an error in replication setup.
DbMon correctly signalled
command failed — Enterprise Replication not active (62)

command failed — Enterprise Replication not active (62)

If you come across this, there is no reason to get panic. It’s a Cisco Bug CSCso82088.

The replication has been successful. You can use the above perf query commands to verify replication status. It should be ‘2’ for good replication.

If replication status still not synches try this:

utils dbreplication stop on sub wait for it to stop.
utils dbreplication stop on pub.

utils dbreplication dropadmindb on pub, wait for syscdr to drop.

utils dbreplication dropadmindb on sub.

Once that is done utils dbreplication reset all from pub.

Another useful command to check replication:

admin:utils dbreplication runtimestate

DB and Replication Services: ALL RUNNING

Cluster Replication State: Only available on the PUB

DB Version: ccm7_1_3_32900_4
Number of replicated tables: 427

Cluster Detailed View from SUB (2 Servers):

SERVER-NAME     IP ADDRESS      (msec)  RPC?    STATUS          QUEUE   TABLES  LOOP?   (RTMT)
———–     ————    ——  —-    ———–     —–   ——- —–   —————–
DAR  172.22.6.x    0.352   Yes     Connected       0       match   N/A     (2)
GOS  172.22.5.x    0.026   Yes     Connected       0       match   N/A     (2)


To check Database Integrity:

show cuc dbconsistency unitydirdb

show cuc tech dbserver integrity


Useful Commands for Cluster:

Show tech network hosts

Show network cluster

Show tech dbstateinfo

utils diagnose test

utils network hosts

utils network host xxxxx – you can put the name of the CCM server which will resolve to ip address. if you put ip address this will give you the name of the server. This will prove that DNS is working correctly.


CCIE Lab is one of the toughest IT exam out there and I believe CCIE Voice is “the” toughest (I am not making this up, this has been acknowledged by Quad/Triple CCIEs) as it involves so many applications which can break and go wrong so easily if you are not good in configuring them. Making everything work in a matter of 8 hours and that too as per Lab directions really need a sound preparation, experience and Strategy.

To be very honest, I just had one year experience in Voice before I started preparing for the exam. I had quite a few books with me which I use to study whenever I got time. I think reading the books filled my experience gap as I build all my concepts from there. Some of the books which are “must have” for a person going for CCIE or want to become a good Voice Engineer are as follows:

  • Troubleshooting Cisco IP Telephony By Paul Giralt (ISBN-10: 1587050757)
  • Cisco Voice Gateways and Gatekeepers By David Mallory (ISBN-10: 158705258X)
  • Configuring Call manager and Unity By David Bateman (ISBN-10: 1587051966)
  • Cisco Call manager Best Practices By Salvatore Collora (ISBN-10: 1587051397)

These are just few books out of many. The more you will read, the more your concepts will get clear which is the key to pass CCIE Lab. I also went through CUCM SRND, CME SRND. I didn’t read word by word of these SRNDs but read enough to get the concept.

Before the Lab Day:

  • Practice as much as possible. Either rent a rack or build your own lab where you can practice. Now where building your own lab is nice but that would cost you a lot of money. Try getting your employer behind you in these kind of expenses. If you don’t have your own lab, don’t worry, this is not end of the world. I think its always helpful if you have a small lab to practice little things and getting use to the kit avoiding waste of time on live rack where every minutes counts. I had a small lab consisting of a Server with VM images of CUCM 7.0, CUC 7.0, UCCX and CUPS. My server had 2GB of memory so I had to load balance my Images across my Server and Laptop (3GB RAM). I had a 3500XL Switch, 1x 2611XM router, 2×7960 and 2×7912 IP phones. Later on one of my friend lend me his 4×7961 IP phones and a 2801 router which I used to connect through VPN to a CCIE Voice rack.
  • The Cisco Lab Blue print is the place to begin with. Start working through the blue print topic by topic. Read books on that topic and forums/google till you understand the concept. I still remember how much I had to read to make my dial-peer/translation rules concepts clear.
  • MGCP, H323 protocols are very important – You must know inside out of how they work, what can go wrong and how you will fix it
  • Call Routing is “the” important section of the Lab. You make mistake here and I assure you another nice lunch with proctor. For Call routing you must understand how a Call routes? How you can change Call routing? where you can make those changes and how it will affect your calling and called party number (I will discuss all this in separate section).
  • CUC and CUE are easiest if they work and are the most difficult if they start playing with you. Get as much practice as possible on these two especially CUE. You must practice to configure CUE using both GUI and CLI.

Lab Day:

  • If you are traveling to the lab then at least get there a day before. If this is your first time then do visit the lab and get a feeling of where you have to reach next day. I still remember my first time when I reached Brussels and it took me more than 2 hours to find lab as I started walking in complete opposite direction. That walk saved me for next day as I reached there before time.
  • Don’t do too much a day before lab. You have already done a lot, few hours are not going to make any difference. Spend the day in making strategy as how you will approach the lab, what first and what second etc..sleep well before your usual time. A good sleep will make you fresh and fast next day.
  • Listen to the proctor what he is saying carefully. When you start the lab, read the instructions right at the beginning very carefully.I wasted my 10-15 minutes on my first attempt only because I was searching for something which was very clearly written on the instructions page. You will always like to start the lab as soon as you can, DON’T, spend sometime reading the lab instructions and the lab questions.
  • Do not spend time on sections which you will do at last. During my first attempt I was caught up by time. I spent too much time at places where I should have not and then I got into some ugly replication issues for which I was not prepared. I could do the whole lab if I had one more hour available to myself but that was not the case. Time allowed is 8 hours and no matter what goes wrong in your lab, you still have to complete the lab within 8 hours. I left some 15 points on the table which I didn’t even attempt and 15 points are enough for you to Fail.
  • Make a note of time when you start something and keep in mind of how much time you are going to spend on it. This is what I didn’t do in my first attempt and I was adamant to make everything work before I move on and that made me pay just for CCIE lunch. During my 2nd attempt there were at least 2 occasions where I found myself standing on thin ice. I spent sometime resolving those two issues but couldn’t resolve it. After spending like 15-20 minutes I said to myself, this is it, move on. I moved on and completed other sections and when I came back I knew exactly what went wrong which I didn’t catch before. This is why I am emphasizing that if you think you have spent too much time on something and you are not getting desired results then move on, you can always come back and check. But if you start spending all your time on every other issue then you will not be left with anymore time to finish the lab I am afraid.
  • When you are reading the lab, make a note of section# and a little name of it on the paper like Section#1.1 VLAN 1.2 DHCP 1.3 NTP and so on. As you complete a section, mark it with one colored pen that its been completed (not verified). You can either finish the whole lab and then check each and everything from scratch or you do this in parallel. I followed the later in my 2nd attempt. I was configuring and then making all possible checks for that particular configuartion and then moving to next section. I then did a grand check in last 1 hour after finishing everything. That final check should be like you are checking someone’s else lab and not your own. Try to find all possible faults in the configuration and believe me you will find something which was not configured properly. I made two changes on my final check, If I had not corrected those two mistakes, I would have failed.
  • For CUCM I followed left to right, Top down approach. I started with Service parameters and Enterprise parameters. Instead of coming to service parameters every time you need to change a parameter, make a list in your head already of what needs to be changed after going through the lab. Change them all in one go and then save it. Make Device pool, CSS, Partitions, Media Resource Group, Voicemail, Users, Phones etc.
  • I Configured gateways one by one and complete. DHCP, VLAN, NTP etc are basic gateway configuration which can be done at start. Then go through the lab and see what is required at what gateway. Which one is MGCP? Which one is H323 or SIP? If it’s an MGCP gateway I will make sure that I have already added it at CUCM to make use of trombone feature. Though you can configure MGCP gateway manually as well but I found trombone feature more helpful. Also make a note if there is any SRST requirement on the gateways. SRST configuration though similar but behave differently between an MGCP and H323 gateway. Need to be careful!
  • Pay special attention to details in lab questions. Every word is there for a reason and if you miss one word that can cost you points.
  • I configured Call Routing and QOS at the end. In my first attempt, even though I think I am quite good in call routing, I made some silly mistakes. On my 2nd attempt, I read the questions and started making a rough call flow on a paper with all ANI and DNIS settings, transformations etc. After quickly making notes of the whole Call routing section, I started to make Route patterns, Route Lists etc and I was quick as I knew exactly what I am doing. I didn’t check any of those till I completed the whole section and then I started checking one by one. Everything worked!  Note: This approach is only recommended if you are good in Call routing otherwise I would advise configure/check approach  – configure a Route pattern, make all checks and then proceed to next one.
  • CUE if its in the lab should be done in parallel with other CUCM configuration. As most of the time CUE work on its own and require several restarts so don’t waste time waiting for CUE to complete.
  • CUPS – Start from Call manager and then jump to Presence Server. Configure the SIP Trunk, Personal Communicator, Service Parameters etc. At Presence, don’t forget to change the name of CUPS Server to IP address as UPC will access it with IP.  Check all services are up. I will explain the CUPS setup on another entry at this blog.
  • It would be good if you do CUPS and UCCX one after other. Both of them take less time and you almost know if its working or not. In UCCX make sure all CTI ports etc are up and registered. Don’t make a new script unless specified. Edit the same script which is already there.  I would recommend you try to complete these two before lunch. I couldn’t do it as I got stuck in a MWI issue but my target was to complete these two before lunch. If you can do Basic CUCM, complete Gateways, Codecs, CUE, CUC, CUPS and UCCX before lunch then you almost nailed the lab. You will be left with CUCM features, Call Routing, some percent of Media Resources, QoS and SRST.
  • Q0S is something you need to be very careful as if you make any mistake in there, it can cock up your other configuration. I attempted QoS at the end. Before starting QoS I saved config ‘wr mem’ of all routers and switch (in case I have to reload the router if anything goes wrong). You  must check Call routing, CUC/CUE, UCCX etc after configuring QoS to make sure there is no bottleneck by QoS configuration. One good command to check your link bandwidth is ‘show frame-relay pvc xxx’.
  • Make sure you check the gateways are registered and ISDN links are all up before leaving the lab – If for any reason your isdn link was down or your gateway got unregistered, you will get no points for it.

Lastly, I would say that CCIE lab is all about determination. Many of you will not pass it in first attempt or may be 2nd attempt as well but if you lose hope and don’t make another attempt then let me assure you that you can never do CCIE. If you fail lab, book your next lab as soon as possible within a span of a month or month and a half. Always make first attempt when you are very well prepared so that you don’t have to spend more time in making 2nd, 3rd attempts if it is required as you will already be prepared and it would be just a matter of brushing up those areas where you lack.

I hope these notes be helpful for those who will be going for CCIE lab.